Groundwater Issues, Remediation and

Modeling

N C GhoshNational Institute of Hydrology, Roorkee

Email : ncg@nih.ernet.in

GW uses in India• Highest in the World

• Meeting 85% of rural domestic requirements, 50% of urban water ,

and more than 60% of irrigation requirements

GW Structures

• 3.9 million in 1951

• 18.5 million in 2001

• 27 million in 2009 (projection)

Growth of

GW Structures

Hydrogeology of India(CGWB, 2006)

Groundwater

provinces

% extent of

total

geographic

area

Himalayan highland

province

12.50

Ganges-

Brahamaputra

alluvium province

15.27

Alluvium & sandstone

discont., and

Precambrian

sedimentaries

14.25

Precambrian

crystalline province

44.45

Deccan trap province

(Basalt)

12.13

Gondwana

sedimentary province

1.40

Sustainable Drinking

Water Supply

GW Challenges – Broadly 7 CsE

nv

iro

nm

enta

l &

Eco

log

ica

l w

ate

r

sup

po

rt

Imp

act o

f clima

te

cha

ng

e

Challenges !

Modification of

surface conditions

Quality threat to

Availability due to geogenic

source of contamination

GW Issues in India

Availability

Supply-side

Groundwater System

Demand-side

Supply-side Issues:

• Modifications of surface conditions,

- transformation of open lands into paved areas, sedimentation and siltation

of water bodies, closure of water bodies, etc.

• Impact of climate change on hydrological variables.- modification in rainfall pattern, intensity & duration, reduction in natural

GW recharge, etc.

• Leaching of contaminants from surface sources.

GW Issues in India .. Contd.

GW Availability Issues :

• Excessive withdrawal leading to groundwater level depletion in

many areas,

- 2009 report: Out of 5842 assessment units, 802 units over-exploited, 189 unit

‘critical’, 523 unit ‘semi-critical, 70 blocks underlain by saline groundwater.

• Quality deterioration due to geogenic source of contamination,- Arsenic , Fluoride, Fe2+, and Inland salinity contaminated aquifers.

• Constrains in geological formations,- 12.5 % Himalayan highland province, 15.3% Ganga & Brahmaputra alluvium

province,14.2% semi-consolidated, and about 58% hard rock formations.

• Seawater ingress threat in many coastal aquifers,- Out of 6100 km coastlines along mainland, Saline water ingress recorded in

Minjur area in Tamil Nadu; Porbandar in Saurashtra region in Gujarat,

8-10 km in Subarnarekha, Salandi, and Brahmani outfalls in Orissa,

Pondicherry region, east of Neyveli Lignite mines.

GW Issues in India … contd.

Demand-side Issues :

• Dependability on GW in rural sector is more, - easily accessible, less risk free, self ownership and no obligation of withdrawal

• Demand increasing in all sectoral uses,- More than 20 million modern groundwater extraction structures reported up to 2001,

By the year 2009, it is expected to be more than 27 million. Data of 2001 showed

57% of tube wells (out of 9 million) in India are in Punjab, Haryana & Uttar Pradesh.

• Conflicts of interest increasing,- Equity in access in different sectoral usages, conflicts in sharing of GW in local

level, etc.

Scientific Issues:

- Uses indiscriminately as a common pool resource- a number of private players

involved – lack of data & information- therefore, a lot uncertainties associated with

analysis.

- Inconsistency with the data collected by different Institutions, Lack of aquifer

formations and aquifer data, No appropriate mechanism for data sharing, etc.

Groundwater Management Challenges

Groundwater over

development &

depletion

Competition within

and between sectoral

uses

Secondary

salinity

Groundwater quality

concerns due to

geogenic sources

Management Challenges

Major alluvial plains

Coastal plains

Hilly areas

Hard rock areas

Anticipated climate

changes

Increasing

demands in all

sectoral usages

Fragmented

approach in uses

Saline water

intrusion

Inequity in access

Inefficient uses

GW Management Constraints

GW

Management

Constraints

No control &

regulation on

Private wells

Farmers rely

mainly on

GW

Licen

sing to

new

estab

lishm

ents

with

ou

t water su

pp

ly

assu

ran

ce lead

to

ad

d n

ew tu

be w

ells

Willin

g to

dig

we

lls

to a

larg

er d

ep

th if

we

lls go

dry

Food security-

livelihoods-energy

subsidy and GW

abstractions are closely

inter-related

Increasing

water market as

Beverages

Lack of aquifer

information on

local scale

Lim

ited

dat

a an

d

un

der

stan

din

g o

n

har

dro

ckh

yd

rog

eolo

gy

and

fra

ctu

red a

qu

ifer

Lim

ited

da

ta a

nd

info

rma

tion

on

coa

sta

l a

qu

ifer

s

an

d G

WQ

Few Experts view on GW

• Municipal demands are not function of urban population but of

economic status as well,

• Lack of basic information/data is one of the causes of GW depletion,

pollution and environmental concerns,

• Lack of a suitable framework for collecting GW data is another

reason.

• Large credit subsidies to agricultural sector have also given rise to

groundwater Structures.

• Groundwater resources likely to be relatively robust in the face of

climate change compared with surface water due to buffering effect

of groundwater storage.

Limited information

base on groundwater

availability, quality,

withdrawal etc.

Groundwater in private

"informal" sector, with

public agencies playing indirect role

CHALLENGES

Groundwater Development

Groundwater Management

application of science & management

Changeover from Development to Management Mode

Components of GW Management

Management

Components

Supply-side

Management

Groundwater System

(Aquifer) Management

Demand-side

Management

Components of supply-side Management

Supply-side

Management

Increase of GW

recharge

RWH & GW Recharge

programs/activities

Maximizing Surface

water for recharge

Rejuvenation of

traditional surface

water bodies

Improving incentives

for water conservation

& artificial recharge

Exploring possibility for

use of partially treated

wastewaters for GW

Recharge

Task

Needs understanding of hydrology, and

geo-morphology.

Components of GW System Management

GW System

(Aquifer)

Management

Estimation of Aquifer

response , rate &

direction of flow and

contaminants

Aquifer parameters and

geometry

Task

Regular/Periodic

monitoring of GW levels

and contaminants’

concentration

Incorporating monitored

data to develop GW

resource mapping

Undertake systematic &

scientific research on

occurrence, use and

ways of augmenting and

mapping the resource

• Needs understanding of groundwater system.

• Modeling is a powerful tool for groundwater

system management.

Components of Demand-side Management

Demand-side

Management

Supply &

Regulation of flow

without violating

technicalities

Need to create appropriate

laws / regulatory mechanism

Governance & priotization

of uses

System of pricing aligning

incentives for ground water

use with goal of sustainability

Promoting innovative

techniques and uses such

as; conjunctive use

Promoting precision

irrigation & water-saving

crop production technologies

Task

Optimization-Simulation modeling is

a powerful tool for demand management.

MANAGEMENT MODEL

Groundwater SimulationModels

+ Optimization Methods

=

Optimize Objectives

Hydrological and hydrogeological

information, data, defining resource and

target properties

Development of Simulation Model

satisfying constraints/resources (Use of

available software modules or development

of new Computer Code)

Evaluate Objective Function

(Minimize Cost ‘Or’ Maximize benefits)

conceptual model

Domain Configuration & development of

conceptual model

Is Target Achieved?

Perturbation for New

Configuration (Genetic

rearrangement)

NO

Management Goal Achieved

Yes

Structure of Simulation-Optimization Framework

Our Weaknesses• Groundwater is a hidden resource; it exists with geological formations;

its space-time availability can precisely be calculated when there are

good databases.

• Lack in good and comprehensive framework of databases, and

institutional mechanisms in sharing of data.

• There are number of Groundwater stakeholders working in isolation,

and duplicating collection of data, and viewing on GW issues in

fragmented ways.

• Lack in coordinated approach between and among major stateholders

of GW resources.

• Our sectoral policies related to water do not coherently supplement

one-another issue.

� There is a need to develop a comprehensive

“Hydro-geologic Information System” .

National Project on “Aquifer Management”

Launched by Ministry of Water Resources, Govt. of India

under 12th Five Year Development Plan.

Objectives :

• identify and map aquifers,

• Quantify available groundwater resources potential,

• propose plans appropriate to scale of demand,

• characterize aquifer and identify institutional arrangements

for management.

� A Noteworthy step towards generating

“Hydro-geological Information System”

National Inter-Departmental Steering Committee (NISC)

Special Purpose Vehicle –Special AQUAM Cell in CGWB

State Ground Water Coordination Committee

(SGWCC)

Technical Service Agency

(TSA)

State Ground Water Resource Centre

(SGWRC)

District Support Organizations

i/c parahydrogeologists

Organogram for the NAQUAM

Ground Water Quality Issues

Disposal of

wastes, leaching of

sewer materials,etc.

Domestic pollution

leaching of

nutrients

pesticides

fertilisers

Agricultural pollution

Disposal of

effluents in

streams or

land

Industrial pollution

Arsenic

Fluoride

Iron

Nitrate

Salinity

Geogenic contamination

Quality deterioration

• Anthropogenic Pollution is controllable - source known

• Geogenic Pollution uncontrollable - source not known

Arsenic contamination in Groundwater

7 States namely : West-Bengal, Jharkhand, Bihar, Uttar Pradesh

in flood plain of Ganga River; Assam and Manipur in flood plain of

Brahamaputra and Imphal rivers ,and Rajnandgaon village in

Chhattisgarh reported Arsenic Affected.

As of 2008; • 9 districts in West Bengal,

• 15 districts in Bihar,

• 3 districts in Uttar Pradesh,

• 1 district in Jharkhand,

• 3 districts in Assam,

• 4 districts in Manipur, and

• 1 district in Chattisgarh

detected for groundwater arsenic contamination > permissible limit of 50 µµµµg/L.

Arsenic contamination in GW

All arsenic affected river

plains have river routes

originated from the

Himalayan region.

Fluoride contamination in GW

Permissible limit : 1.5 mg/l

25 million population of

16 states are affected by

Fluoride contamination in GW.

6 million children below the age

Of 14 years.

Assam, J & K, Kerala, Delhi,

Orissa,Bihar, Haryana,

Karnataka,Maharastra, M.P.,

A.P., Gujarat, Rajasthan,

Tamil Nadu, and U.P.

Other Groundwater quality Problems

� Salinity – parts of Andhra Pradesh, Bihar, Gujarat, Haryana, Karnataka, Kerala, M.P., Chhatisgarh, Maharashtra, Orissa, Punjab, Rajasthan, Tamil nadu, U.P., NCT Delhi. (15 States)

� Nitrate - 11 states, covering 95 districts.

� Iron – Assam, West Bengal, Orissa, Chattisgarh, and Karnataka and localized pockets in state of NE, Bihar, UP, Punjan, Rajasthan, Maharastra, Madhya Pradesh, Jharkhand, Tamil Nadu and Kerala. (15-States).

Few sustainable techniques• Bank Filtration for sustainable drinking water supply

Advantages:

• Soil acts as filtering media;

• Naturally treated;

• Reduces post-treatment cost;

• Less expensive;

• No chemical addition,

• Reduce Pathogenic load.

Technicalities:

• Perennial stream/river

• Distance of well from riverbank

• Alluvial formations;

• Retention time.

Concerns :

• Riverbed Clogging;

• Aquifer Clogging. Potential RBF sites

In India (Saph Pani)

Sustainable solution Contd..

• 22 Wells located 15 m – 250 m away from River & Upper Ganga Canal

• Bottom well caisson : 7 – 10 m; Wells operated : 19 to 24 hours

• Travel time : 2 to 100 days

RBF site in Haridwar

Sustainable solutions contd..• Managed Aquifer Recharge and Soil Aquifer Treatment

• Monsoon surface runoff conservation and recharge to potential

aquifer after addressing water quality aspects and subsequent

recovery of recharged water can provide a solution.

• Storm water conservation from urban areas after addressing WQ

aspects can also be a potential source for aquifer recharge.

• Municipal wastewater from urban areas after appropriate treatment

can also be considered for aquifer recharge and subsequent recovery

of groundwater .

Conclusions

• India is the highest groundwater user in the World. Uses of GW

will continue to rise in future due to competing sectoral demands.

• Until recently, the focus was mainly on groundwater development,

emerging issues and challenges compelled to orient focus towards

groundwater management.

• Objectives of groundwater management can not be achieved, unless

there is enforced law on control and regulation.

• Groundwater related problems as that because of overexploitation ,

are more due to lack of ‘knowledge and information’.

• Development of a comprehensive “Web enable Hydro-geologic

Information System” will help reducing conflicts on uses of

groundwater, and its judicious management.

• Optimization-Simulation modeling is a powerful tool that can be

used as a Decision Support System for GW Management.

Leonardo da vinci stated;

“The greatest river of the planet earth flows underground”.